I've said it before and I'll say it again, Ryan is da man.
It's worth saying that the best test for magnetic properties is a magnet. The actual scientific and engineering theory and practice of practical magnetism is more than a little iffy. No matter how sure you are, never let theory overrule reality. It's bad science.
The martensetic autensetic thing may have been oversimplified (by me). Steels can have a fair bit of nickel and still be magnetic, and none at all and not be magnetic. Further, the amount of cementite ain't in it. When you get down to the nitty-gritty, it's really a matter of how the atoms are bound into molecules and the molecules into the steel lattice -- as to whether atomic shells and nuclei are amenable to re-orientation at all, and whether they'll hold the new orientation.
If you want to know about something specific, test it with a magnet. Easy enough, just buy a little refrigerator magnet and carry it along with you.
That said, the overwhelming majority of knives are magnetic enough to stick on a good knife bar. Almost all steell alloys which are adequate for knives are. Steels which are formulated to be so corrosion resistant they are incidentally non-magnetic are usually too soft to be useful. The one class of steel knives with a significant number of exceptions is probably dive knives.
The knives should be oriented with the spines facing in one direction only, so that putting the knives down on the bar spine first, and rolling them off edge first becomes unthinking habit. That will protect the knives and the bar.
FWIW, I keep my most often used knives in a block on the counter, and the next most frequently used used knives on a mag-bar under the potrack and above some bookcases (no counter there). I've used a knife bar off and on for decades and haven't found that it does damage to the knives or that it's insecure for any of the knives I've had (and I've had a lot of them).
BDL